1. Field of the Invention
This invention relates to sensors of the type that are used in lance-type shot peening guns. Such structures of this type, generally, measure the reaction force of the ejected shot and air stream which are emitted from the lance-type shot peening gun. The sensor further supplies diagnostic information indicative of the shot peening process performance.
2. Description of the Related Art
The need for a shot peening process monitor is well known. Exemplary of such shot peening process monitors is U.S. Pat. No. 4,805,429 ('429) to R. A. Thompson, entitled "Shot Peening System and Method with Velocity Sensing" and assigned to the same assignee as the present invention. The '429 patent describes the importance of measuring shot velocity as well as having a gun mounted process monitor. The '429 patent discloses a gun mounted reaction force sensor to gather the information required to meet the needs for conventional shot peen guns. Lance-type shot peening guns, however, are different than conventional guns.
In general, lance-type shot peening guns are connected to pressure pot machines. The lance-type guns consist of a tube at the end of which a tungsten carbide deflector faces a hole in the tube wall at an angle of 45.degree. to the tube's axis. Thus, shot swept through the lance at high velocity by high pressure air is deflected at right angles to the lance's axis and propelled against the workpiece. In addition, the long slender lance tube (about 1/2" in diameter.times.12" long) is often tailored by bending to reach areas which are inaccessible to conventional guns, for example, the inside of bores. For these reasons, the force sensing scheme used in the '429 patent is not readily adaptable to lance-type shot peening guns. Therefore, a more advantageous sensor, then, would be presented if the reaction force sensor were adaptable to lance-type shot peening guns.
It is apparent from the above that there exists a need in the art for a sensor which is capable of measuring the reaction force due to the ejected shot and air from the shot peening gun, and which at least equals the measuring characteristics of the known conventional shot peening guns, particularly those of the highly advantageous type disclosed in the above-reference Thompson patent, but which at the same time is capable of being adapted to a lance-type shot peening gun. It is a purpose of this invention to fulfill this and other needs in the art in a manner more apparent to the skilled artisan once given the following disclosure.